Cognitive load theory (CLT), developed by John Sweller in the 1980s, is one of the most influential frameworks in educational psychology. It applies what we know about human cognitive architecture — particularly the limited capacity of working memory and the vast capacity of long-term memory — to the design of instructional materials. The central principle is that learning is most effective when instructional methods minimize unnecessary demands on working memory while directing cognitive resources toward schema construction and automation.
Three Types of Cognitive Load
Intrinsic load is determined by the inherent complexity of the material and the learner's prior knowledge — it reflects the number of interacting elements that must be processed simultaneously. Extraneous load results from poor instructional design that forces learners to engage in processing unrelated to learning (e.g., searching for relevant information in a cluttered display). Germane load represents the cognitive effort devoted to constructing and automating schemas — the productive processing that leads to learning.
CLT has generated numerous instructional design principles: the worked example effect (studying worked examples is more effective than solving equivalent problems for novices), the split-attention effect (integrating related information sources reduces load), the redundancy effect (eliminating redundant information improves learning), the modality effect (using both visual and auditory channels expands effective working memory capacity), and the expertise reversal effect (techniques effective for novices can become counterproductive for experts). These effects have been replicated across domains from mathematics to medicine.
Practical Applications
CLT has transformed instructional design in education, training, and multimedia learning. It provides evidence-based guidelines for designing textbooks, e-learning platforms, and training programs. The theory has been particularly influential in medical education, where complex material often overwhelms working memory, and in multimedia learning, where Mayer's cognitive theory of multimedia learning extends CLT principles to the design of visual and auditory instructional materials.